Evione Lighting LAB upgrade.

Well what can I say.

After many loaners and loads of help from a friend I have finally completed my Lab using all my own gear and some of my gear has been upgraded.

I have upgraded my soldering station to a full digital temp controlled unit and a SMD reworking station which allows me to work with smd and modern lighting equipment including pocket wizzards and the like.

I also have acquired an XProtolab oscilloscope for those odd little experiments or times that I need one to analyze a circuit.

I have assembled a 6 Channel Logic Analyzer which is PC based and am in the process of assembling a PC based O.Scope as well.

My bench PSU’s have grown to 4 after building 3 very specific units for the work I do.

I have also acquired some decent quality Digital Multimeters which is awesome as the one I was using was a sub R200-00 cheapie. :-P Hey it worked well.

Evione is ready to undertake any repairs that you may need to your photographic lighting. 

Evione Light Sabre V1.0

Wow. After much experimenting and trying various forms of controlling output of high powered LED’s I have finally completed the design and am in the process of building the final unit.

I will be demoing and making use of this prototype over the next few weeks for my photographic work to test the durability and battery of these lights. Thereafter they will be produced for sale market.

 

Specs as follows:

• 10Watt High Powered LED.
• 4400mah 11.1V Lithium Polymer Battery. (Gives a run time at full power of 4.5 hours)
• Super High CRI rating of 98% +
• Daylight balanced at 5600K
• Flicker Free for use on video and photography
• Variable Digital Power Control in 25 steps (Allows greater control of lighting)
• Super Diffusion material and Bouwens Mount adaptor so you can mount all your accesories.

Photographs of this light will follows soon as well as sample images taken with this light.

AD9850 DDS Chip Experiment

Today I decided to do some experimenting with the Chinese AD9850 Module and pulled out the trusty Freeduino which is permanently on my breadboard as a prototyping setup.

 

This is the module on the top and Freeduino on the bottom. Wiring up this little board is really simple. I am going to use 4 pin control of the board so therefore we only need four jumpers between our Freeduino/Arduino and the module.

• Arduino Pin 8 – Module CLK (Clock) Pin
• Arduino Pin 9 – Module FQ (Frequency Update) Pin
• Arduino Pin 10 – Module DATA (Serial Data Load) Pin
• Arduino Pin 11 – Module RST (Reset) Pin

 

Thats it from the wiring up perspective. Now instead of re-inventing the wheel I have found several sources of good code already made for running these boards quiet well and considering this is not a final production circuit there is no harm in showing what is already out there.

 

The Sketch:

/*
* A simple single freq AD9850 Arduino test script
* Original AD9851 DDS sketch by Andrew Smallbone at www.rocketnumbernine.com
* Modified for testing the inexpensive AD9850 ebay DDS modules
* Pictures and pinouts at nr8o.dhlpilotcentral.com
* 9850 datasheet at http://www.analog.com/static/imported-files/data_sheets/AD9850.pdf
* Use freely
*/
#define W_CLK 8       // Pin 8 - connect to AD9850 module word load clock pin (CLK)
#define FQ_UD 9       // Pin 9 - connect to freq update pin (FQ)
#define DATA 10       // Pin 10 - connect to serial data load pin (DATA)
#define RESET 11      // Pin 11 - connect to reset pin (RST).
#define pulseHigh(pin) {digitalWrite(pin, HIGH); digitalWrite(pin, LOW); }
// transfers a byte, a bit at a time, LSB first to the 9850 via serial DATA line
void tfr_byte(byte data)
{
  for (int i=0; i<8; i++, data>>=1) {
    digitalWrite(DATA, data & 0x01);
    pulseHigh(W_CLK);   //after each bit sent, CLK is pulsed high
  }
}
// frequency calc from datasheet page 8 = <sys clock> * <frequency tuning word>/2^32
void sendFrequency(double frequency) {
  int32_t freq = frequency * 4294967295/125000000;  // note 125 MHz clock on 9850
  for (int b=0; b<4; b++, freq>>=8) {
    tfr_byte(freq & 0xFF);
  }
  tfr_byte(0x000);   // Final control byte, all 0 for 9850 chip
  pulseHigh(FQ_UD);  // Done!  Should see output
}
void setup() {
// configure arduino data pins for output
  pinMode(FQ_UD, OUTPUT);
  pinMode(W_CLK, OUTPUT);
  pinMode(DATA, OUTPUT);
  pinMode(RESET, OUTPUT);
  pulseHigh(RESET);
  pulseHigh(W_CLK);
  pulseHigh(FQ_UD);  // this pulse enables serial mode - Datasheet page 12 figure 10
}
void loop() {
  sendFrequency(55.e6);  // freq
  while(1);
}

 

As you can see in the above sketch that the frequency can be controlled with the command sendFrequency(55.e6); with 55 being the frequency that you are wanting.

The above code places the device on 55Mhz and powers it on.

My spectrum annylyzer screenshots below:

As you can see above there  is no signals on 55Mhz.

After powering up the Freeduino and module you can see the spike on 55Mhz clearly which means this little fella is outputting a nice 55Mhz. Please note that there is no antenna or power amp on the output of the circuit so this is just the modules output showing up.

The frequency is also almost spot on. Very impressed with this little board. More to follow when I start actually replacing Oscillator circuits in old two way radios :-P Some fun could be had.

Designing A Drive & Control Circuit for High Powered L.E.D’s

Well it has been a crazy few months with editing weddings and such however I have still managed to find time enough to design, develop and write the program for the microcontroller for my version of the now famous Ice Light.

The Design of my light had a few things that needed to be met:

1. It had to be adjustable in steps such as how photographic lighting works.
2. It had to be over 1000 lumen to make it usable on camera equipment that did not have great ISO performance. Also the light would be put through diffusion which would weaken it.
3. It had to be portable and re-chargeable and the batteries needed to be light and readily available.

Now I also did some homework and have improved considerably over the Ice Light design by using even higher quality LED’s. CRI rating of the LED is even more important than the temperature of the light. CRI is your colour rendering index and most LED gear is below 80 CRI. The Ice Light is 90 CRI and above. I have located and been testing a 98+ CRI LED and the results are outstanding. It is a 5600K 98+CRI 1 Watt LED module. You must remember that Colour Temperature can be corrected in camera or post however lack of certain colours is a little harder.

The light produced by these modules is fantastic. The colour rendering is amazing in comparison to any other artificial light source I have ever tried.

Then the project began on how to drive these LED’s as they are current sensitive devises and just throwing power on them will mean a short life for the LED. You have to limit the current to the max level that the LED specifies. In my case with test LED’s it was 12V and 900ma max. I did some testing and found the difference in light between 900ma and 700ma was marginal but the increase in heat was a lot. I therefore decided to limit myself at 700ma.

I have been building and testing various drivers over the last few weeks and have finally found something that I enjoy using. It really does simplify my task.

Then there was the LED control circuit. Sure I could just throw a variable resistor on a mosfet and use that to vary the power of my light but I wanted to make this thing better than any other light out there and one of my pre requisites was that the light could be controlled in steps. The reason for this is you could easily set two light at the same level or adjust ratios as you have preset levels.

Dont get me wrong as using logics I can give said light around 255 levels which would make it almost analogue but this would be a pain to manage for the end user.

I made up my mind to use at ATMEGA 328-p as they are readily avail and easy to program. I also used the Arduino platform to design and test but the actual end unit is a standalone ATMEGA controller with a few components around it. Why waste an entire Arduino board after all.

I ran into many many issues while playing with these circuits and also due to lack of sleep managed to blow a ATMEGA CPU and a few other bits and bobs so if you want more information on how I got this lot to work WELL. Drop me a message and ill help you out.

 

Cheers for now

 

Dionne

DIY 1.0V to 24V – 1.5 Amp Project Power Supply

Hey everyone.

It is weird that after many in-active years with my electronics that I managed to jump straight back into it without much problem.

Anyway I (before acquiring my large dual rail PSU) needed a small lowish current variable power supply in order to test and work on my various projects. These things costs a small fortune in the store. So this small project was born.

At first I decided that a simple LM317 could supply more than enough power for the type of projects I was looking to work on. Well it is but that is for another post.

I drew up the schematic in Eagle which is where I do most of my design work.

I eventually assembled the Regulator control board on my breadboard and low and behold she worked beautifully. The only problem was at full load the LM317 got pretty hot. Well to cut a long story short The LM317 and the 7805 that powers the logic board have been mounted to a heatsink which I salvaged from a none working UPS. They do get warm now but not hot per say.

This Vero board with Heatsinked LM317 can be seen below:

The other veroboard on the top left of the case is the 5V supply for the logics as well as the voltage and current sensing circuit which brings the signal to within spec for the ATMEGA to be able to read on its analogue inputs.

I first built a fully functional unit with the ATMEL on a breadboard however I did not like the build even though it worked well and decided to use an okd serial Arduino board and removed the female pin headers and replaced with male pin headers. I then programmed the ATMEGA328-P on one of my other Arduino’s and placed it into circuit.

All alignment of volts and amps is done via the 3 buttons on the back of the case which puts you into setup mode and allows you to fine tune. No variable resistors or such to fiddle with.

 

FIRST VERSION MOUNTED TO VEROBOARD:

SECOND UPGRADED VERSION WITH OLD SERIAL ARDUINO:

In the above and below images I am aligning and setting the unit to within spec.

   

Close enough for me. I also verified and tuned again using my Fluke DMM as well. Hell for what I need it for its more than within spec.

Well this is the end result.

She is back on her spot on the bench and raring to go. Alongside her big sister…. :-P

The Engineer is Reborn.

After spending many years as a RF Radio / Cellular engineer for various companies and doing my time as a site technician as well as bench repair technician I pulled away from the IT and Electronics fields as most in the RF game where not enjoying the hours and work. Don’t get me wrong the learning was amazing but I could earn more money on other fields which where not as intensive.

Now just a little history about me. I studied electronics and digital systems engineering at Tech after finishing my schooling at George Campbell Technical High. I have since a very young age always been a tinkerer. This is probably due to my best mates dad being a Ham radio operator. Hell at 9 years of age I was stripping our ICL Elf 8088 PC to see how it works.

Yes photography has always been something I loved but electronics seemed the logical way for me.

Now many many years on after completely dropping my electronics I find my Professional Photography field and electronics coming together and I have lately started developing my own lighting and electronics which will assist me with my photography career.

The engineer has been reborn and maybe just in time. More Blog posts to follow.

If you would like to know more about my photography please head on over to www.dionneswart.com where you can check out my photography work.

Cheers for now

 

Dionne

Setting up the LAB…

All electronics tinkerers need a lab of sorts. The lab gear is rather expensive but if you know what you are doing you can setup a decent lab at a decent price.

Below is both my Photography & Electronics work area. This setup works great for either work.

I also spend most of my time doing my Photo editing on my Macbook Pro.

The PC is running a modified form of SDR based on the RTL based DVB-T Receiver. It can receive everything from around 50Mhz to around 2.4ghz. I use it for listening to Radio and testing small oscillators etc. Basically it is my spectrum analyzer.

On the left is a dual rail 0-30V – 3amp per rail bench Power supply. This is what I use for all my tinkering and designing. I also have a 15amp sitting below the desk which is fixed at 13.8V and on the bench you can see me doing a few more updates to the hardware and software of my 0-12V- 1.5A digital Power supply which I built myself from scratch before acquiring the big fella on the left. This little fella lives under the left side of the left screen.

 

As you can see the little guy was rather simple but did what I needed. I have since added a current sensing circuit and updated the code on the ATMEGA 328 which drives this guy. New Display is below.

Besides adding the current measuring section I have also added 3 buttons to the back of the case which allows me to calibrate the units AMPS and VOLTS without opening and adjusting. All calibration is done in software and written to the E2PROM of the ATMEL ATMEGA328-P CPU.

You can see the buttons on the top right of the image above. You can also see the old serial Arduino which I was going to turf as its just a pain to use. I programmed the ATMEGA on my of my other boards and just plugged her in. I seriously need to find a better way to interface as I used all recycled electronics to build this guy. Except the Veroboard, case and a few fittings.

 

Anyway enough about my tinkering for the moment.

I have just had a tough day of photo editing in 35 Deg C temperatures with humidity levels as high as 90 percent.

 

Cheers for now.

 

Dionne